Aptitude - Pipes and Cistern - Discussion
Discussion Forum : Pipes and Cistern - General Questions (Q.No. 3)
3.
A pump can fill a tank with water in 2 hours. Because of a leak, it took 2
hours to fill the tank. The leak can drain all the water of the tank in:
hours to fill the tank. The leak can drain all the water of the tank in:Answer: Option
Explanation:
| Work done by the leak in 1 hour = |  |
1 | - | 3 |  |
= | 1 | . |
| 2 | 7 | 14 |
Leak will empty the tank in 14 hrs.
Discussion:
90 comments Page 7 of 9.
Mouni said:
10 years ago
I can't understand how 7/3 is converts in to 3/7?
Juned shah said:
1 decade ago
/*Other method to solve this problem */.
A, A-l.
Time 120, 140.
Time/min 7, 6.
Capacity 840, 840 of tank.
So due to leakage difference in time/min (7-6) = 1.
So 840/1 = 840 min.
Convert it in hr.
= 840/60 = 14 hr.
& This is our require answer.
A, A-l.
Time 120, 140.
Time/min 7, 6.
Capacity 840, 840 of tank.
So due to leakage difference in time/min (7-6) = 1.
So 840/1 = 840 min.
Convert it in hr.
= 840/60 = 14 hr.
& This is our require answer.
Bunty said:
1 decade ago
For those who didn't got that how 7/3 come from?
Here it is 2*1/3 hours means (2*3+1)/3 = 7/3.
Here it is 2*1/3 hours means (2*3+1)/3 = 7/3.
Priya said:
1 decade ago
I had one doubt if suppose they are asking to find when the tank is filled due to its leakage means how to solve it? Please can anyone explain?
Anjali said:
1 decade ago
A pump can fill a tank with water in 2 hours. Because of a leak, it took 2 hours to fill the tank. No where it is written that its taking 2.20 mints to fill while after leakage. Then why everyone taking (7/3). I am lost. Do help.
Elizabeth said:
1 decade ago
@PGCR.
Very well explained. Thank you :).
Very well explained. Thank you :).
Sandeep said:
1 decade ago
Lets us simplify by doing it minute basis:.
Let the Volume be V without leak tank is filled in 120 min.
So, in 1 min = V/120.
With leak, = V/140.
Leak is withdrawing water per min = V/120 - V/140 = V/840.
i.e 840th part is filled in 1 min.
So the tank is filled in 840 min i.e. 14 hours.
----------------------------------------------------------------Hour Basis,
In 1 hour V/2 with leak, 3V/7.
Work by leak = V/2-3V/7 = V/14.
V = 14 h.
Let the Volume be V without leak tank is filled in 120 min.
So, in 1 min = V/120.
With leak, = V/140.
Leak is withdrawing water per min = V/120 - V/140 = V/840.
i.e 840th part is filled in 1 min.
So the tank is filled in 840 min i.e. 14 hours.
----------------------------------------------------------------Hour Basis,
In 1 hour V/2 with leak, 3V/7.
Work by leak = V/2-3V/7 = V/14.
V = 14 h.
MGH said:
1 decade ago
@Mohanpriya.
Why have we done the calculation till 140 mins?
Why have we done the calculation till 140 mins?
Govindarajan said:
1 decade ago
20 mins extra for 2 hour i.e. 120 mins.
120 mins is first tank.
140 mins is second tank.
120/x = 140/20.
140/20*120 = 840 mins.
1 hour = 60 mins.
14 hours = 14 hours.
120 mins is first tank.
140 mins is second tank.
120/x = 140/20.
140/20*120 = 840 mins.
1 hour = 60 mins.
14 hours = 14 hours.
Mohanapriya said:
1 decade ago
2 hrs compose 120 mins.
But due to leak it takes 120+20 = 140 mins.
1st 2hr - 20 goes of [the amount has to be filled in 20 mins].
4nd hr - 40 mins.
6th hr - 60 mins.
8th hr - 80 mins.
10th hr - 100 mins.
12th hr - 120 mins.
14th hr - 140 mins.
And so it takes 14 hours to empty a full tank.
But due to leak it takes 120+20 = 140 mins.
1st 2hr - 20 goes of [the amount has to be filled in 20 mins].
4nd hr - 40 mins.
6th hr - 60 mins.
8th hr - 80 mins.
10th hr - 100 mins.
12th hr - 120 mins.
14th hr - 140 mins.
And so it takes 14 hours to empty a full tank.
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